When people want to grow at work, they usually think of a course, a class, or a certificate. Those things have a place, but they are a small slice of how skill really gets built. A well known model called 70-20-10 lays out the fuller picture. It says that about seventy percent of growth comes from doing the actual work, twenty percent from other people, and ten percent from formal training. The exact split is a rough guide, not a law of nature. Still, it points at a truth that most careers end up proving out.
The model came out of research in the 1980s from a leadership center in North Carolina. Researchers asked successful managers where they learned the lessons that shaped them. The answers pointed again and again to hard jobs and real challenges, not to seminars. From that came the rough breakdown that stuck, seventy, twenty, and ten. Over the years the numbers have been repeated so often they almost sound official. They are best treated as a reminder of proportion, not a precise formula to obey. The spirit of it matters more than the digits.
The largest share, the seventy, is the work itself. People grow most when they are handed a task a little beyond their current reach. A stretch project, a new role, or a problem with no clear answer forces you to learn by doing. You make mistakes, you fix them, and the lesson sticks because it cost you something. This is why a year in a demanding job can teach more than a shelf of books. If you want to grow, the first question is not what class to take, but what harder work to take on. Growth lives on the edge of what you can already do.
The next share, the twenty, is other people. This is the learning that comes from watching, asking, and getting honest feedback. A good manager who tells you the truth about your work is worth more than most training budgets. Mentors, peers, and even difficult bosses all teach in ways a slide deck cannot. Much of this happens in small moments, a quick correction, a story over lunch, a review of what went wrong. The trick is to stay open to it and to actually ask, since few people offer this freely. You have to go looking for the truth about yourself.
The smallest share, the ten, is formal training. Courses, books, and workshops are not useless, they simply are not where most growth lives. Their real value is to give you a frame or a set of words that you then carry back to the job. A class on managing people means little until you use it on a real team next week. Training works best right before you need it, not stored up for someday. Treated as a starting point rather than the finish line, that ten percent earns its keep. Learn the idea, then go put it to work.
Knowing this changes how you plan your own growth. If you keep signing up for courses but stay in the same safe role, you are living off the smallest slice. Real progress means seeking out work that scares you a little and people who will tell you the truth. Ask for the project no one else wants, or the account that is a mess. Find one person whose feedback you trust and make it easy for them to give it. The map says most of your growth is waiting in places a classroom never reaches. Go stand in those places on purpose.
If you manage people, the model reshapes how you build them. You cannot train someone into a stronger employee with courses alone. You grow them by handing over real work, with enough support that they can stretch without breaking. Pair them with people who model the skills you want them to gain. Save the formal training for the moments it will actually land, right as they take on something new. A leader who only sends people to workshops is using one tenth of the tools on hand. The rest of the toolbox is the work itself.
The 70-20-10 model is not exact, and you should not treat the numbers as gospel. Some roles lean more on formal training, and the right mix shifts from person to person. But the core message holds up across careers and fields. Most of what you learn, you learn by doing, with a strong assist from the people around you. Courses matter, just not as much as the sales pitch for them suggests. Plan your growth around real work and honest feedback first, and the rest tends to fall into place.
